A new solid superacid catalyst, Ce-ZrO2/SO42- was prepared simply by doping ZrO2 with Cc and modifying with sulfate simultaneously. The characterization of prepared catalysts was performed using FTIR, XRD and DSC. The surface area of 5Ce-ZrO2/SO42- calcined at 650 degrees C was very high (121.2 m(2)/g) compared to that of undoped and only sulfated ZrO2 (56.0 m(2)/g). This high surface area of Ce-ZrO2/SO42-was due to the doping effect of Ce, which makes zirconia a stable tetragonal phase as confirmed by XRD. 5Ce-ZrO2/SO42- containing 5 Wt-% Ce(SO4)(2) and calcined at 650 degrees C exhibited maximum catalytic activities for both reactions, 2-propanol dehydration and cumene dealkylation. The catalytic activities for both reactions were correlated with the acidity of catalysts measured by the ammonia chemisorption method. The role of Ce was to form a thermally stable solid solution with zirconia and consequently to give high surface area and acidity of the sample. (C) 2006 Elsevier B.V. All rights reserved.